Manual play electronic visual games are well-known in the art. Representative disclosures of typical electronic visual games, and associated display circuitry, can be found in U.S. Pat. No. 3,631,457 to Hamada, et al.; U.S. Pat. No. 3,659,284 to Rusch; U.S. Pat. No. 3,659,285 to Baer, et al.; and U.S. Pat. No. 3,793,483 to Bushnell. The typical manual play electronic visual game is of the hockey type or a paddle type game sold under the trademark "PING-PONG". The game is adapted to be played by a pair of players. Each player has a control unit, which he can use to control a cursor or paddle image, which is movable on a television or cathode ray screen. The cursor usually can be controlled in a single direction of movement only (for instance, up and down). The game circuitry also generates a puck or ball image, commonly a small square, which moves across the screen or "playing field". The circuitry which controls the ball calculates angles of incidence and reflection to duplicate as closely as possible conditions under which an actual game might be played. The players are able to move their paddles along a single direction in order to deflect the moving square back into the other player's field of play. Normally, if the moving square and the cursor of a particular player do not intersect, the moving square moves behind the cursor; and a point is scored in favor of the opposite player. Thus, games similar to tennis, Ping-Pong or volleyball can be played.
Other more complicated games involve games somewhat similar to hockey in that they involve making a shot in a particular specified goal area in order to accure points. In these types of games, each of the players commonly controls a forward cursor and a number of rear cursors, which can act as blocking cursors. However, the basic principles of the game remain the same.
Oftentimes, a person wishes to play an electronic visual game and cannot find another person who is willing to play with him. The player, of course, can choose to manipulate both controls and thereby play both sides of the game himself, but this is often an uninteresting game and the player may soon tire of this game.
It is, therefore, desirable if the electronic visual game has some facility to enable a person to play against the game itself. For instance, a rapidly moving goalie, moving back and forth in front of a goal mouth which starts at unpredictable positions when the ball image is served, may provide a challenge to a player so that he would enjoy playing against the game itself.
What is needed then, is a circuit which would generate control signals to generate a moving goalie, or paddle image, passing in front of a goal mouth.